Investment Securities - Schedule of Amortized Cost, Gross Unrealized Gains, Gross Unrealized Losses and Estimated Fair Values of Fixed-Maturity Securities (Detail) - USD ($) $ in Thousands	6 Months Ended	12 Months Ended
	Jun. 30, 2016	Dec. 31, 2015
Schedule of Trading Securities and Other Trading Assets [Line Items]
Total fixed-maturity securities, Amortized Cost	$ 87,904	$ 99,088
Total fixed-maturity securities, Gross Unrealized Gains	140	78
Total fixed-maturity securities, Gross Unrealized Losses	(5)	(111)
Total fixed-maturity securities, Estimated Fair Value	88,039	99,055
Unrestricted Fixed-Maturity Securities [Member]
Schedule of Trading Securities and Other Trading Assets [Line Items]
Total fixed-maturity securities, Amortized Cost	58,260	66,481
Total fixed-maturity securities, Gross Unrealized Gains	16	14
Total fixed-maturity securities, Gross Unrealized Losses	(1)	(11)
Total fixed-maturity securities, Estimated Fair Value	58,275	66,484	[1]
Fixed-Maturity Securities Held in Trust [Member]
Schedule of Trading Securities and Other Trading Assets [Line Items]
Total fixed-maturity securities, Amortized Cost	29,644	32,607
Total fixed-maturity securities, Gross Unrealized Gains	124	64
Total fixed-maturity securities, Gross Unrealized Losses	(4)	(100)
Total fixed-maturity securities, Estimated Fair Value	29,764	32,571	[1]
U.S. Government Treasury Securities [Member]
Schedule of Trading Securities and Other Trading Assets [Line Items]
Total fixed-maturity securities, Amortized Cost	249	249
Total fixed-maturity securities, Gross Unrealized Gains	1
Total fixed-maturity securities, Gross Unrealized Losses		(1)
Total fixed-maturity securities, Estimated Fair Value	250	248
Obligations of U.S. Government Sponsored Enterprises [Member]
Schedule of Trading Securities and Other Trading Assets [Line Items]
Total fixed-maturity securities, Amortized Cost	60,463	69,392
Total fixed-maturity securities, Gross Unrealized Gains	18	13
Total fixed-maturity securities, Gross Unrealized Losses		(23)
Total fixed-maturity securities, Estimated Fair Value	60,481	69,382
Corporate Debt Securities [Member]
Schedule of Trading Securities and Other Trading Assets [Line Items]
Total fixed-maturity securities, Amortized Cost	18,833	21,048
Total fixed-maturity securities, Gross Unrealized Gains	100	62
Total fixed-maturity securities, Gross Unrealized Losses	(3)	(49)
Total fixed-maturity securities, Estimated Fair Value	18,930	21,061
Foreign Corporate Debt Securities [Member]
Schedule of Trading Securities and Other Trading Assets [Line Items]
Total fixed-maturity securities, Amortized Cost	8,359	8,399
Total fixed-maturity securities, Gross Unrealized Gains	21	3
Total fixed-maturity securities, Gross Unrealized Losses	(2)	(38)
Total fixed-maturity securities, Estimated Fair Value	$ 8,378	$ 8,364

[1] Balances derived from audited financial statements as of December 31, 2015.